Fecal transplants have been a hot topic of discussion in the past year, a fact that may be unsettling for the poop-talk adverse. Recent research has suggested they could be used to treat gastrointestinal conditions like IBS, or even alter the metabolism and impact obesity.

But why all the hype about transplanting poo? And what can it really do?

Fecal transplants are used to treat Clostridium difficile colitis, or C. diff. for short. C. diff. colitis is inflammation of the colon caused by the bacteria Clostridium difficile. It happens when the normal bacteria balance in the gut is disrupted, usually as a result of antibiotic use, Linda A. Lee, M.D., clinical director of the division of gastroenterology and hepatology and director of the integrative medicine and digestive center at Johns Hopkins Medicine, tells SELF. "Antibiotics disrupt the community balance. As a result, you lose diversity." For most people, these bacteria communities rebound pretty quickly after the meds are done. But for other people, the pathogens can't bounce back. "As a result, Clostridium difficile sets up housekeeping and starts to multiply because the good bacteria aren’t there to keep it in check," Lee explains. The bacteria produces a toxin that makes us sick with bad diarrhea, which can be life-threatening in some populations, mostly the elderly or those with immunodeficiencies. C. diff. also produces spores, which travel easily and make the infection quite contagious in settings like hospitals.

C. diff. is treated with targeted antibiotics, but it can be hard to kick because spores hang around in the body and are resistant to the drugs. Recent strains have also started to become resistant to antibiotics. This can cause vicious recurrent diarrhea and even death. But it's been proven that fecal transplants can cure C. diff. infections.

Where antibiotics fail, a transplant of poop can work wonders.

Transplanting stool with a healthy bacteria population into someone with recurrent C. diff. helps re-diversify it and clear up the infection. "Patients are given the choice to identify their own donor, who has to be screened very carefully to make sure they're not at high risk," Lee says. She likens the rigorous process to donating blood. You can also choose to use commercially prepared stool, which hospitals get from companies like OpenBiome that screen donors, prep stool, and ship it frozen. Stool can then be transplanted one of three ways: through a colonoscopy, enema, or nasoduodenal tube (a tube that's inserted through the nose and goes down to the small intestine). Most people prefer the first, Lee says. "You get to be sedated, and there isn't that 'yuck factor.'" It's a quick and easy outpatient procedure.

Fecal transplants for C. diff. have a huge success rate.

After one fecal transplant, there's an 89 percent chance you'll be cleared of C. diff. And it works quickly. "Seventy percent of patients will say that within three days of getting the transplant, they've formed a solid stool." For some, it may take longer. After eight weeks post-transplant, a stool test is done, and if it's clear of C. diff., the transplant is deemed a success, Lee says. For those who still test positive, doctors might decide to do a second transplant. The success rate then jumps to 91 percent.

A handful of other potential uses are being studied, but unfortunately, there's no telling yet if the risks will outweigh the benefits.

"Even though we screen donors carefully for stool pathogens, there could be things we don’t know about yet," and therefore, aren't even looking for, Lee says. "It took us 30 years to identify hepatitis C, so how do we know there aren’t things we haven't discovered yet [in stool]?" There's also the potential for transmitting a chronic illness that a donor has yet to show signs of. Given evidence that gut bacteria could play a role in depression, it’s conceivable that even mental illness could be passed through poop, she says. We really don't know the long-term implications yet. Treating C. diff. is the only clinical use for fecal transplants approved by the FDA. All other fecal transplants can only be done in a research setting. Lee mentions that two recent studies looking into fecal transplant's effect on IBS did not show the positive results researchers hoped for. "It's not clear the benefits outweigh the risks for other conditions, and nobody knows what the efficacy is."

But that could change one day. Studies are still exploring what else fecal transplants can do—particularly when it comes to altering metabolism. Some research suggests they may even help manage allergies. OpenBiome is experimenting with turning the poop into pill form in a way that maintains its effectiveness. Other researchers are looking into harvesting individual helpful bacteria strains from feces. "This way we can grow [the specific pathogen] in a lab and don’t need to use other pathogens" in the transplant, Lee says. So while the uses are limited now, as researchers continue to explore the power of poop, we can probably expect it to continue making headlines.